1. Field of the Invention
The invention is directed to a driver""s cab suspension for commercial vehicles wherein the cab is supported on the vehicle frame by at least two springs at the front of the cab and at least one spring at the rear of the cab, a stabilizer arranged transversely to the frame opposing roll movements of the cab.
2. Description of the Related Art
GB 2,014,522 discloses an air suspension system for driver""s cabs of commercial vehicles having four air springs supporting the driver""s cab. Additional air springs are used for roll stability. The air suspension system can be used in driver""s cabs for conventional cab vehicles and for forward control vehicles.
The xe2x80x9cScania Model T cabxe2x80x9d has a 4-point air suspension combined with a stabilizer. The stabilizer extends transversely in a front region of the driver""s cab. The engine of the vehicle takes up considerable space, so that the stabilizer must be mounted so as to be elevated in supports. Understandably, these supports must absorb considerable forces. Consequently, the supports have a correspondingly heavy-duty construction. Further, the stabilizer extending over the engine impedes access for maintenance and repair work and limits freedom of design in the hood region.
It is the object of the present invention, to provide a driver""s cab suspension, particularly for a conventional cab vehicle, which favorably utilizes the given installation space and in which simple supporting elements can be used for the driver""s cab suspension.
According to the invention, this object is met in that the stabilizer extends in the rear end area of the driver""s cab.
The construction of the bearing support for the stabilizer is appreciably simplified in this advantageous mounting location. In a conventional cab vehicle, the center of gravity of the driver""s cab lies in the rear area. Accordingly, the dimensioning of the driver""s cab structure is greater in the rear area, which makes for a more favorable introduction of force from the stabilizer into the driver""s cab. Further, in many conventional cab vehicles, the vehicle width is smaller in the front region of the driver""s cab than in the rear end area. Consequently, a longer stabilizer can be used in the rear end area than in the front area, which leads to advantages by definition.
In order to be able to achieve the best possible roll stability in principle, the springs are fastened to the outer side of the vehicle frame and the stabilizer is longer than the outside distance between air spring units. The supporting effect of the springs is positively influenced by the external fastening.
In another advantageous construction, the driver""s cab has four air spring units and the stabilizer is in an operative connection with the two air spring units in the end area of the driver""s cab.
In this connection, a simple assembly and small number of structural component parts are achieved in that the air spring suspension and an end of the stabilizer share a common connection bearing to the driver""s cab.
Alternatively or in combination with a common connection bearing to the driver""s cab, a frame-side connection bearing of the air spring unit and a frame-side swivel bearing of the stabilizer form a constructional unit.
Further, it is provided that the air spring unit and a vibration damper together form a spring strut. A valve for supplying or letting off air for the air spring can be arranged directly inside the air spring unit in order to further optimize space and reduce structural component parts.
In order to minimize loading for the passengers of the driver""s cab in the event of an accident, the fastening of the vibration damper is carried out as a predetermined deformation point which enables angular movement of the vibration damper when the load exceeds a normal operating load. In this way, the driver""s cab can displace along the longitudinal axis of the vehicle frame within limits and can remove a considerable portion of the crash impact.
According to an advantageous embodiment, the predetermined deformation point is formed by a clamp in which the vibration damper is clamped.
Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be farther understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein.